大豆分离蛋白-卡拉胶-黄原胶三元复合Pickering乳液的制备与特性分析

Preparation and Characterization of Pickering Emulsion of Soybean Protein Isolate-Carrageenan-Xanthan Terpolymer

本研究制备大豆分离蛋白(Soybean protein isolate,SPI)-卡拉胶-黄原胶三元复合Pickering乳液,考察不同SPI与卡拉胶-黄原胶配比、乳液pH、卡拉胶质量浓度、黄原胶质量浓度以及大豆油内相体积对三元Pickering乳液体系的粒径、Zeta电位、乳化活性指数(Emulsifying activity index,EAI)、乳化稳定性(Emulsifying stability index,ESI)和SPI二级结构的影响,并研究常温贮藏条件下不同内相体积乳液体系的特性变化。结果表明:当SPI与复合多糖的质量浓度比为1:10,pH为9.0,卡拉胶和黄原胶质量浓度均为0.2%,油相体积为10%~85%时,SPI-卡拉胶-黄原胶三元复合Pickering乳液的稳定性均较好,平均粒径达351±24.12 nm,Zeta电位绝对值达99.4±1.4 mV。随着大豆油内相体积从10%增大至85%,Pickering乳液颗粒的粒径分布更加均一、稳定,当油相体积分数为75%时,乳液颗粒分散状态最佳,EAI和ESI达到最大值,SPIα-螺旋和β-折叠含量最高。常温贮藏实验表明,随着时间的延长,不同内相体积Pickering乳液粒径整体呈升高趋势,Zeta电位的绝对值、EAI和ESI整体呈下降趋势;所有乳液的α-螺旋含量和β-转角含量有所下降,β-折叠有所增加,无规卷曲含量变化不明显;内相体积75%和85%的高内相乳液较10%~50%的乳液显示出更好的稳定性。综上,本研究探讨了SPI-卡拉胶-黄原胶三元复合Pickering乳液的制备及特性表征,为功能性物质靶向递送和脂肪代替物应用创新提供了技术参考。

In this study,the Pickering emulsion of soybean protein isolate(SPI)-carrageenan-xanthan terpolymer was prepared.The effects of ratio of SPI to carraneenan-xanthan,pH,mass concentration of carraneenan,mass concentration of xanthan and volume of soybean oil on the particle size,Zeta potential,emulsifying activity index(EAI),emulsifying stability index(ESI)and SPI secondary structure of Pickering emulsion system were all investigated.Besides,the characteristics of emulsion system with different volume of inner phase during storage at normal temperature were studied.The results showed that the stability of Pickering emulsion of SPI-carrageenan-xanthan terpolymer was good,when the mass concentration ratio of SPI to the complex polysaccharide was 1:10,pH was 9.0,the mass concentration of carrageenan and xanthan both were 0.2%,and the oil volume was 10%~85%.Under this conditions,the average particle size of Pickering emulsion of SPI-carrageenan-xanthan terpolymer was 351±24.12 nm,and the absolute value of Zeta potential was 99.4±1.4 mV.As the inner phase volume of soybean oil increased from 10%to 85%,the particles size distribution of Pickering emulsion became more uniform and stable.When the oil volume was 75%,the dispersion state of emulsion particles was the best,EAI and ESI reached the maximum,andα-helix andβ-fold contents of SPI were the highest.In addition,the storage experiments at normal temperature showed that the particle size of Pickering emulsion with different volume of inner phase showed an overall increasing trend,and the absolute value of zeta potential,EAI and ESI showed an overall decreasing trend with the storage time extending.Theα-helix content andβ-angle content of all emulsions decreased,whileβ-folding increased,and random crimp content did not change significantly.High inner phase emulsions with 75%and 85%inner phase volume showed better stability than those with 10%~50%inner phase volume.In conclusion,this study explored the preparation and characterization of Pickering emulsion of SPI-carrageenan-xanthan terpolymer,aimed to provide technical reference for targeted delivery of functional substances and application innovation of fat substitutes.